Effect Of Thickness Of Gravel Covering Surface On Water Loss And Plant Growth Of Dump In (Semi) Arid Area

At present,great progress has been made in the ecological restoration of mining areas in China.The prospect of ecological restoration in mining areas is optimistic,but the task is arduous.There are a large number of dumps located in(semi)arid areas.Doing a good job in the ecological restoration of mining areas in(semi)arid areas is of great significance to build a resource-saving and environment-friendly society and promote the comprehensive,coordinated and sustainable development of economy and society.Therefore,this thesis studies the effect of thickness of gravel covering surface on water loss and plant growth of dump in(semi)arid area,in order to reduce the soil water loss and promote plant growth of dump,and improve the ecological restoration effect of dump in(semi)arid area.In order to study the influence of overburden thickness on soil water loss,based on the theory of soil water evaporation,the soil water loss test under the influence of overburden thickness was carried out.According to the long-term observation data,with the help of relevant soil moisture and overburden performance indicators,the influence law of overburden thickness on relevant indicators is revealed.The results show that,the overburden has an obvious inhibitory effect on soil water loss.The soil water loss rate decreases with the increase of overburden thickness,but the increase of overburden thickness will improve the interception rate of overburden.Therefore,when overburden thickness affects soil water,it plays a "double-edged sword" role.The soil water loss test under the influence of overburden thickness laid the foundation for pot planting test.The overburden has obvious inhibitory effect on soil water loss.In order to study the influence of overburden thickness on plant growth and reveal the influencing factors of plant growth under different overburden thickness,the pot planting experiment under the influence of overburden thickness was carried out.Soil humidity-temperature monitor,relevant plant growth status and soil property indicators determination were carried out.The results showed that,the difference of plant growth under the influence of overburden thickness was significant,and T2 group had the most significant effect on plant growth;The difference of soil properties under the influence of overburden thickness is small;The change characteristics of soil water and heat under the influence of overburden thickness are significantly different.Overburden can increase or reduce soil temperature and change soil inverse humidity;The influencing factors of plant growth in the presence of overburden are summarized,and the influence mechanism of overburden thickness on each factor is expounded.In order to study the influence of overburden thickness on plant germination and the influence of slope position and precipitation conditions on plant growth under different overburden thickness,the experiment of plant germination and growth under the influence of overburden thickness were carried out.Based on the plant germination experiment,the relevant plant germination indexes were measured.The results showed that,during plant germination,although overburden had an obvious inhibitory effect on the overground part of plant,it was beneficial to promote the growth and development of roots;Based on the plant growth experiment,taking the platform,the upper of slope,the middle of slope,the lower of slope as the research object,the relevant plant growth indexes were measured.The results showed that,the existence of overburden produced the slope ecological effect affecting the plant habitat.In terms of the number of yellow leaves,the ecological interference on the upper of slope was the least intense,the number of green leaves under different overburden thickness was the largest on the platform;According to the maximum plant height variation evaluation system,the comprehensive optimal thickness of different planting areas under high-frequency precipitation is T3,T1,T2 and T1 respectively,and the comprehensive optimal thickness of different planting areas under low-frequency precipitation is T1,T1,T2 and T3 respectively.The influence of gravel overburden on the sequence structure and surface properties of ecological restoration is expounded;the parameters that should be considered in overburden construction are pointed out.This thesis analyzes the construction links of ecological restoration overburden of dump in(semi)arid area,mainly including the collection and stockpiling of overburden materials,plant planting and overburden laying,and puts forward the basic requirements and specifications of each link.Taking Heidaigou open pit coal mine as an example,this thesis introduces the application background of the construction of ecological restoration overburden in its dump,discusses the main links involved in the construction cost of overburden,analyzes the production cost according to the constituent elements,and evaluates the expected ecological and social benefits.By carrying out the construction of ecological restoration overburden of dump in(semi)arid areas,take a sustainable development ecological restoration road in line with national conditions,mining conditions and geological conditions,so as to realize the sustainable development of environment,resources and human beings.The thesis has 31 figures,25 tables and 92 references.